1. Field of the Invention
The invention relates generally to photographic cameras and in particular to those cameras for use with a film cartridge having a projecting film leader. More particularly, the invention relates to improved means for ensuring that the projecting film leader is properly positioned in a film feed path when the cartridge is loaded in the camera.
2. Description of the Prior Art
Recently, Fuji Photo Film Co., Ltd., has made available several drop-in loading (DL) 35 mm cameras. In a DL type camera, the film cartridge is inserted in an axial direction through a bottom opening into a loading chamber of the camera. At the same time, the film leader projecting from the film cartridge is transversely received in a film feed path which extends between the loading chamber and a film take-up chamber in the camera. Typically, the forward end of the film leader extends sufficiently into the take-up chamber to partially overlap a take-up spool in that chamber.
When the film cartridge and projecting film leader are received in a DL type camera, it is important to have the cartridge properly positioned in the loading chamber and to have the leader properly positioned in the feed path and the take-up chamber before a back door of the camera is closed. If the film leader is skewed, i.e., runs at an oblique angle, from the egress opening of the cartridge or the cartridge is not completely received in the loading chamber, the leader can be trapped out of its proper position when the back door is closed. As a result, a film metering sprocket in the feed path may not be able to engage the film leader at its perforations or the sprocket may rip the leader at its perforations as the sprocket attempts to advance the leader. Similar problems can occur when a toothed take-up spool in the take-up chamber attempts to take-up the forward end of the leader.
In commonly assigned U.S. Pat. No. 4,332,453, granted June 1, 1983, there is disclosed a DL type camera having a cartridge positioning member which is disposed on a bottom door of the camera to depress the film cartridge in the axial direction in the loading chamber as the door is initially closed. The cartridge positioning member ensures that the film cartridge is properly positioned in the loading chamber before the bottom door and a coupled back door are completely closed. The two doors are closed by pivoting them about parallel axes which extend lengthwise along the body of the camera.
The Fuji DL-50 camera has cooperating means which are disposed on the camera body adjacent the film feed path and on the back door, respectively, for transversely positioning the film leader to straighten it in the event the leader is skewed from the feed path. The cooperating means function to transversely position a skewed leader in response to closure of the back door, and they comprise a ramp on the camera body which is inclined towards the feed path and a pressure plate on the back door. The pressure plate has a cut-out which is shaped to admit the ramp as the back door is closed. When the film leader is skewed, it overlaps the ramp. Thus, as the back door is closed, a skewed leader will be forced by an edge portion of the pressure plate which defines the cut-out to slide down the ramp, thereby transversely positioning the film leader to straighten it along the feed path.
In a DL type camera, such as the Fuji DL-50 camera, the back door is pivotally connected to the camera body at a location between the take-up chamber and an end of the camera body closest to the take-up chamber. Consequently, as the back door is initially closed, a guide member on the back door will be moved to a position for urging the forward end of the film leader into engagement with a toothed take-up spool in the take-up chamber before the edge portion of the pressure plate which defines the cut-out can cooperate with the ramp on the camera body to straighten the leader in the event it is skewed. The forward end of the leader, therefore, may become trapped between the guide member and the take-up spool, thereby preventing the leader from being straightened in the event it is skewed. At this point, even if a cartridge positioning member, such as described in U.S. Pat. No. 4,332,453, for depressing the film cartridge in an axial direction in the loading chamber were employed it would do little to correct the position of the leader. Thus, the metering sprocket in the feed path and the toothed take-up spool will not operate to advance the leader, and the camera user may not be aware of this failure during picture-taking.